Single- or multiple-row cylindrical roller bearing

ABSTRACT

A roller bearing including inner and outer races defining an interior space therebetween, and a plurality of cylindrical rollers between the races, each race having opposite axial end surfaces, a seal situated at each end of the bearing, each seal including a loosely fitting flange ring extending radially between the races, the ring having an inner axial surface facing the axial end surface of the inner race, thereby defining facing end surfaces, the ring and the inner race respectively having bore surfaces, the inner race having at least one hole extending generally radially from the bore thereof to the interior space for supply lubricant to the interior space, and pressure equalizing passages communicating the interior space with the exterior of the bearing, the openings comprising at least one passage in one of the facing surfaces and at least one axial passage axially traversing the ring.

This application is a division of application Ser. No. 08/652,313, filedMay 23, 1996, now U.S. Pat. No. 5,660,483.

BACKGROUND OF THE INVENTION

The invention concerns a single- or multiple-row cylindrical rollerbearing consisting of two concentric races that at either axial end haveradial flanges facing one another, where in each instance one of thefacing radial flanges of a flange pair is provided with a seal whichwith the facing flange forms a sealing face, and of cylindrical rollersrolling between the races, and which is provided with holes for thesupply of oil mist and with pressure-equalizing openings for ventilationof the bearing.

In cylindrical roller bearings the end faces of rolling members rollalong the faces of fixed flanges or flange plates. Sliding frictionoccurs there the magnitude of which can be reduced only when sufficientlubricant can reach these areas. This is not always ensured inhigh-speed rolling bearings that are lubricated with oil mist.

It is known that in cylindrical roller bearings lubricated with oil mistat least one of the flanges may be provided with a plurality of passagesrunning axially, where these passages, at least several of which areclosed with removable stoppers, are arranged in the radial regionbetween the raceway of the associated race and the sealing ring (DE-PS3,223,007).

At the same time, these passages, which serve for ventilation,preferably are arranged at pitch circle level, i.e., in the region ofthe midpoint of the rollers. This means that the oil mist as a rule onlyreaches this region and not the region of the raceways or even thetransitions of raceways and the flanges, where adequate lubricationwould be very desirable.

The object of the present invention is to avoid this disadvantage and toprocure a cylindrical roller bearing wherein even the raceways and, inparticular, the critical areas at the transition from raceway to flangeare sufficiently supplied with lubricant.

SUMMARY OF THE INVENTION

According to the invention, this object is accomplished in that thepressure-equalizing passages are arranged in the radial region betweenthe raceway and the bore surface of the associated race. In this way itis provided that the oil mist reliably reaches the region of the racewayand, in particular, the region of transition between raceway and flangeside face.

According to another feature of the invention, the pressure-equalizingpassages may be arranged running radially between the raceway and boresurface of the associated race.

With loosely fitting flanges the pressure-equalizing passages preferablymay be formed by a surrounding annular groove which is in communicationwith the interior space of the bearing, and at least one connectingchannel starting from said interior space and communicating with theexterior. At the same time, according to additional features of theinvention, the annular groove may be incorporated either into the flangeat the face turned toward the associated race or in the race itself atthe face turned toward the associated flange.

Starting from this annular groove, the connecting channels may bedesigned as through holes running axially or as axial grooves running inthe region of the bore surface.

Various examples of the invention, which are to be described in detailbelow, are represented in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a partial longitudinal section through a multiple-rowcylindrical roller bearing;

FIG. 2 shows a detail in the longitudinal section of FIG. 1 on anenlarged scale;

FIG. 3 shows a sectional view of the example of the present invention ofFIG. 1;

FIG. 4 shows another example in partial longitudinal section;

FIG. 5 shows a detail in the longitudinal section of FIG. 4 on anenlarged scale; and

FIG. 6 shows a sectional view of the example of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The cylindrical roller bearing of FIG. 1 consists of the outer race 1,which at either axial end has a radial flange 2 formed in one piece withthe race 1, the inner race 3 which is provided with a loosely fittingflange ring having a radially outward extending edge 4 facing the flange2, as well as two rows of cylindrical rollers 5 rolling between theraces 1 and 3. Loosely fitting flange ring 4 has a peripheral groove 6,in each instance open toward the fixed flange 2, in which slottedsealing ring 7 engages with little play. These sealing rings 7 areprestressed to bear against the flanges 2 of the outer race 1. The innerrace 3 is provided with holes 8, through which oil mist is supplied tothe bearing interior.

As can be seen in FIGS. 2 and 3, the loosely fitting flange ring 4 atthe surface toward the inner race 3 in the radial region between theraceway 9 and the bore 10 is provided with a surrounding annular groove11, which projects slightly beyond the raceway 9. In communication withthis annular groove 11 are a plurality of ventilating grooves 12,distributed at the periphery and running radially, which in the regionof the bore 13 open into grooves 14 running axially. In this wayventilation of the bearing interior is ensured through the annulargroove 11 and the grooves 12 and 14.

In the example of FIGS. 4 to 6 a surrounding annular groove 11 isprovided in the loosely fitting flange ring 4 at the face turned towardthe inner race 3. A plurality of passages 15, running axially anddistributed on the periphery, open into the said annular groove 11. Inorder to produce a communication to the exterior despite the axialshoulder 16 against which the loosely fitting flange ring 4 rests, theflange ring 4, on the face turned toward the shoulder 16, is designedwith a plurality of radial grooves 17 distributed on the periphery andin communication with the passages 15.

While in the examples described above, the supply andpressure-equalizing openings are provided in or in the region of theinner race, it is anyway possible to provide them in the region of theouter race raceway or on the facing sides.

What is claimed is:
 1. A cylindrical roller bearing comprising inner and outer races and respective raceways defining an interior space therebetween, said races having at either axial end radial flanges facing one another forming a flange pair, where in each instance one of the facing radial flanges of said flange pair is provided with a seal which with the facing flange forms a sealing face, and a plurality of cylindrical rollers between said races, said inner race provided with at least one hole for supplying an oil mist, and one of said flanges comprising a loosely fitting flange ring which is provided with said seal, and wherein said bearing further comprises pressure-equalizing passages for ventilation of the bearing formed by an annular groove in said flange ring which is in communication with the interior space of the bearing and at least one connecting channel extending from said interior space and communicating with the exterior of the bearing, said connecting channel comprising a hole extending axially in communication with said annular groove.
 2. A cylindrical roller bearing comprising inner and outer races and respective raceways defining an interior space therebetween, said races having at either axial end radial flanges facing one another forming a flange pair, where in each instance one of the facing radial flanges of said flange pair is provided with a seal which with the facing flange forms a sealing face, and a plurality of cylindrical rollers between said races, said outer race provided with at least one hole for supplying an oil mist, and pressure-equalizing passages for ventilation of the bearing, characterized in that the pressure-equalizing passages are situated in the radial region between an axial end of the outer race and one of said flanges adjacent thereto and where the radial region extends between the raceway and bore of said outer race. 